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In short: there's no such policy. It's always the same amount following the simple rules posted in the answer.
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Shadow WizardMar 29 '12 at 8:54

Also worth to mention in this context - after enough downvotes on certain user posts, he will get automatic ban - either questions or answers - if he/she does not have enough upvotes as well.
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Shadow WizardMar 29 '12 at 8:56